Buffer Overflow in Azure RTOS USBX Host Stack

CVE-2022-29223 · CRITICAL Severity

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Azure RTOS USBX is a USB host, device, and on-the-go (OTG) embedded stack. In versions prior to 6.1.10, an attacker can cause a buffer overflow by providing the Azure RTOS USBX host stack a HUB descriptor with `bNbPorts` set to a value greater than `UX_MAX_TT` which defaults to 8. For a `bNbPorts` value of 255, the implementation of `ux_host_class_hub_descriptor_get` function will modify the contents of `hub` -> `ux_host_class_hub_device` -> `ux_device_hub_tt` array violating the end boundary by 255 - `UX_MAX_TT` items. The USB host stack needs to validate the number of ports reported by the hub, and if the value is larger than UX_MAX_TT, USB stack needs to reject the request. This fix has been included in USBX release 6.1.10.

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